I have android application.I want to add new information in every month and I want to delete old ones in device. How can I do it?

I did an android application, its about the pharmacy on duty. I want to change it in every month but when I download it my device from google store, it shows the old month information. So what can I do for delete old month information and show new month information? Here is my code for this app.

import android.app.Activity;
import android.content.ContentValues;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.widget.TextView;
import static com.ahmety.eczanezonguldak.Sbtalapli.*;

public class Alapli extends Activity { 
private Vtalapli data;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.alapli);


data = new Vtalapli(this);
try{addData("","","","");
addData("17.06.2015","Pharmacy Name ","pharmacy addres","pharmacy tel no");   
Cursor cursor = getData();
showData(cursor);
}
finally{
data.close();
}
}



private void addData(String date, String pharmacy, String address, String tel){

SQLiteDatabase db = data.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(DATE, date);
values.put(PH,pharmacy);
values.put(ADDRESS,address);
values.put(TEL,tel);
db.insertOrThrow(TABLE_ALAPLI, null, values);
 }

private static String[] SELECT = {DATE, PH, ADDRESS,TEL};
private Cursor getData(){
SQLiteDatabase db = data.getReadableDatabase();
Cursor cursor = db.query(TABLE_ALAPLI, SELECT, null, null, null, null, null);

startManagingCursor(cursor);
return cursor;
}

private void showData(Cursor cursor){
StringBuilder builder = new    StringBuilder("                                                                  Nöbetçi Eczane/Alapli\n\n\n "
+ "  Tarih                      Eczane                                            Addres                                           Tel\n");

while(cursor.moveToNext()){

String date = cursor.getString((cursor.getColumnIndex(DATE)));
String ph = cursor.getString((cursor.getColumnIndex(PH)));
String address = cursor.getString((cursor.getColumnIndex(ADDRESS)));
String tel = cursor.getString((cursor.getColumnIndex(TEL)));

builder.append(date).append("    ");
builder.append(ph).append("  ");
builder.append(address).append("  ");
builder.append(tel).append("\n");
}

TextView text = (TextView)findViewById(R.id.textalapli);
text.setText(builder);

}
}